正交试验法优选木犀草素的β-环糊精包合工艺

以正交试验法对木犀草素的β-环糊精包合工艺条件进行了优选。结果显示 ,该包合工艺的最佳条件是 :木犀草素与β-环糊精的比例为 1:1,包合温度为 60℃ ,包合时间为

壳聚糖絮凝法精制补肾养血颗粒水提液的工艺研究

目的优选壳聚糖精制补肾养血颗粒水提液的工艺。方法以淫羊藿苷为指标,应用高效液相色谱法测定其含量,采用正交设计法考察加水量、提取时间、提取次数对水提工艺的影响;以淫羊藿苷为指标,结合总多糖含量,选择药液浓度、絮凝温度、澄清剂加入量3个因素,优选壳聚糖的絮凝澄清条件。结果最佳水提工艺条件为A_2B_1C_3,即加入10倍量水,提取3次,每次1 h;最佳絮凝工艺为A_2B_1C_3,即药液浓度为0.4 g/m L,絮凝温度为40℃,壳聚糖加入量为0.1%。结论本研究优选的精制工艺稳定可行。

硫酸二乙酯诱变保加利亚乳杆菌最佳条件的研究

通过对硫酸二乙酯(DES)对保加利亚乳杆菌的诱变条件进行研究,以致死率为指标确定了最佳诱变条件,结果表明在DES剂量为0.8%、诱变时间为30min、诱变温度为37℃、菌液浓度为107个/mL的条件下诱变,致死率可达到99.1%。

基于仿真的汽车发动机再制造生产线缓冲区容量优化

以汽车发动机核心部件为对象,以在制品数量(WIP)为主要评价指标,重点研究回收件到达率、可再制造率、加工时间等不确定因素对缓冲区容量的影响.基于离散事件仿真技术建立系统动态运行模型,采用正交试验设计方法完成了仿真试验的方案设计.通过仿真再制造生产线动态平衡及缓冲区容量的内在变化规律,获得生产线优化运行所需的最小缓冲区容量.案例研究表明,所提出的方法能有效确定再制造系统缓冲区的最佳容量.

Extraction and Content Determination of Shikimic Acid in Pinus elliottii Engelm

[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 （5 μm,4.6 mm × 150 mm） column separation;the mobile phase was acetonitrile-2%H3PO4 （90：10）;the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows：ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1：25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.

Process parameters optimization of Ti-6Al-4V alloy sheet during hot stretch-creep forming

Hot stretch-creep forming （SCF） is a novel technique to produce hard-to-form thin-walled metal components. Comprehensively considering the analysis results of the springback angle, yield strength and microstructure, four hot SCF process parameters including temperature, stretch velocity, post stretch percentage and dwelling time of a Ti-6Al-4V alloy sheet were optimized using an orthogonal experiment. The results reveal that temperature is the most important factor on springback angle. The yield strength of the deformed material in 0° direction increases, while those in directions of 45° and 90° fluctuate around the original value. After hot SCF, the shape of some a phases changes from short thin grains to long slender ones, and the microhardness changes very little. The optimized parameters with temperature of 700 ℃, stretch velocity of 5 mm/min, post stretch percentage of 2% and dwelling time of 8 min are achieved finally.

Major factors controlling nitrous oxide emission and methane uptake from forest soil

Soil samples were taken from depth of 0-12 cm in virgin broad-leaved Korean pine mixed forest in Changbai Moun-tain in July 2000. The effects of temperature, soil water content, pH, NH4+ and NO3- on N2O emission and CH4 uptake of a for-est soil were studied in laboratory by the method of orthogonal design. It was observed under laboratory conditions in this study that there were significant correlations between N2O emission rate, CH4 oxidation rate, soil pH and temperature. Nevertheless, N2O emission rate also showed a significant positive correlation with CH4 oxidation rate. The results suggested that pH and temperature were important factors controlling N2O emission and CH4 oxidation under this experiment conditions.

Optimal Conditions for the Purification of Sesamin by Recrystallization

[Objective] Sesamin has been widely used in healthy food and medicines in recent years due to its prominent biological functions. This study was aimed to determine the optimal parameters for sesamin recrystallization, to obtain high-quality and high-purity sesamin. [Method] The effects of solid-liquid ratio, heating tempera- ture and cooling temperature on sesamin recrystallization were investigated by sin- gle-factor experiments and orthogonal array testing （ORT）. The purity of resulting sesamJn was investigated by HPLC, [Result] The optimal conditions for the purifica- tion of sesamin were solid-liquid ratio of 1：10, heating temperature of 45 ℃ and cooling temperature of 25 ℃. Under these conditions, the purity of sesamin reached 95.26%. [Conclusion] Recrystallization is an effective technique to purify sesamin from sesame meal. Moreover, HPLC is also an ideal method for analyzing the purity of sesamin.

Springback and tensile strength of 2A97 aluminum alloy during age forming

The analysis of variance(ANOVA), multiple quadratic regression and radial basis function artificial neural network(RBFANN) methods were used to study the springback and tensile strength in age forming of 2A97 aluminum alloy based on orthogonal array. The ANOVA analysis indicates that the springback reaches the minimum value when age forming is performed at 210 °C for 20 h using a single-curvature die with a radius of 400 mm, and the tensile strength reaches the maximum value when age forming is performed at 180 °C for 15 h using a single-curvature die with a radius of 1000 mm. The orders of the importance for the three factors of pre-deformation radius, aging temperature and aging time on the springback and tensile strength were determined. By analyzing the predicted results of the multiple quadratic regression and RBFANN methods, the prediction accuracy of the RBFANN model is higher than that of the regression model.

Establishment of a Multiplex PCR System for Detecting Transgenic Ingredients from Citrus

[Objective] This study aimed to establish a multiplex PCR system for de- tecting transgenic ingredients from Citrus. [Method] Based on the pBI121 plasmid sequences published in GenBank and actin gene sequence of Citrus, the primers specific to CaMV35S promoter, NOS promoter, NOS terminator and actin gene were designed, to establish a multiple PCR system which could detect four types of sequences. In addition, orthogonal tests were performed to determine the optimal concentrations of all the components in PCR reaction system, as well as the optimal PCR cycle parameters. [Result] The optimal PCR reaction system should contain 2.5μl of 10xPCR buffer, 2.0μl of MgCI2 （25 mmol/L）, 2.0 μl of dNTP mixture （2.5 mmol/L of each dNTP）, 1.0 μl of actin gene primers （10μmol/L）, 1.0μl of 35S promoter primers （10 μmol/L）, 1.5 μl of NOS promoter primers （10 μmol/L） and 0.5 μl of NOS terminator primers （10μmol/L）, 0.1 μg of template DNA, 1.25 U of Taq DNA polymerase; ddH20 was added to the total reaction system of 25μl. The PCR reaction program consisted of pre-denaturing at 94℃ for 5 min; 31 cycles of denaturing at 94℃ for 30 s, annealing at 64.1℃ for 45 s and extension at 72℃ for 50 s; final extension at 72℃ for 10 min. The reaction system optimized with the orthogonal tests could detect as less as 0.1% transgenic component in the tested samples. [Conclusion] The MPCR detection system established in this study can meet the requirements in theory for detecting the genetically modified ingredients in Citrus or the deep-processed products.

Effect Research of Immobilized Algae-bacteria Removal Ammonia Nitrogen of Aquaculture Wastewater and Proposed Model

Applied Immobilized algae bacteria (ABI) to remove ammonia of freshwater aquaculture wastewater. Temperature (T),PH,light intensity (I),dissolved oxygen (DO) and filling rate five factors plays important role in the process of ammonia nitrogen removal ,related data between ammonia removal and five factors was received through multi-factor orthogonal test,and established relations model between the five factor and nitrogen removal. The results show that five-factors had significant effect on AR,and the best combinations for removing AR was temperature 30 ℃,pH=7.0,light intensity 6 000 lux,dissolved oxygen 5.0 mg/L and the fill rate 10%. According to the experimental data,equation model was proposed and coefficient of determination R2 =0.864 8,P<0.05. Samples T-test was done between the model predictions and the actual measured values.Test results showed that the significant difference of overall mean value sig. (2-tailed) was 0.978 (P>0.05),it Shows that had no significant difference between model predictions and the actual measured value,and model had a high degree of fitting.

CUTTING FORCES FOR HIGH-SPEED DRILLING OF COMPOSITES

The thrust and the torque of various carbide drills are studied for the high-speed drilling of fiber reinforced epoxy composites. The orthogonal experiment is carried out with different feed speeds at high rotation speed. Experimental results show that the spindle rotation speed is the most influential factor. The thrust andthe torque decrease under the condition of high rotation rate. With the decrease of the feed speed, the thrust and the torque decrease. But the effect of the feed speed is less than that of the spindle rotation rate. Moreover, the effect of drill materials on the thrust and the torque is more notable than that of the drill geometries and the feed speed. The thrust is greatly affected by the feed speed while the torque is obviously affected by drill geometries.

Study on Effects of Different Factors to Eggs Hatching Rate of Cryptotympana atrata by Orthogonal Design

[Objective] The paper aimed to explore influence of different factors on eggs hatching of Cryptotympana atrata,and optimize technical parameters in practice.[Method] By using hatching rate as index,L16（44）orthogonal design was employed to determine the effects of the four factors including temperature,salinity,photoperiod and pH.[Result] Photoperiod had obviously effects on hatchability of Cryptotympana atrata eggs.The optimal conditions for hatching were temperature 30 ℃,salinity 25%,photoperiod L12∶D12,and pH 6.[Conclusion]The research provided some scientific basis for indoor artificial incubation.

Optimization of the Formula of Maca Lozenges by Orthogonal Test

The orthogonal experimental design was used to optimize the formula of maca lozenge and explore the preparation techniques and product property of maca lozenges. With the sensory evaluation of maca lozenge as the indicator, L16 （44） orthogonal design graph was used to select the optimal techniques, and to investigate the stability, heavy metals and microorganisms contents in the tablets. The optimal formula was 80% of maca power, 12% of Rhodiola rosea powder, and 6% of Angelica sinensis powder, where the comprehensive sensory index reached 246. Moreover, under the optimal conditions, various kinds of heavy metals contents were in consistent with the GB164740 standards, and there was no significant change in color, size, friability, and disintegration time, as well as microorganism content during the 12-month preservation. With simple, easy and reliable technique and quality control method, the process study had obtained the national patent process （patent number： ZL200810233796.X）, and the contents of heavy metals and micr6organisms laid foundation for the quality standard.

Optimization of PCR Reaction System for Random Single-strand DNA Pool in SELEX Technology

[Objective] This study aimed to optimize the PCR amplification conditions for random ssDNA pool in SELEX technology. [Method] L16（45） orthogonal experimental design was adopted for optimization of five important factors affecting PCR reaction system for random single-stranded DNA pool including Mg2＋ concentration, dNTP concentration, amount of Taq DNA polymerase, primer concentration and amount of random single-stranded DNA pool at four levels. Meanwhile, the annealing temperature and number of PCR reaction cycles were optimized to establish the optimal reaction system and PCR procedure. [Result] The optimal combination of PCR reaction system for random ssDNA pool was obtained, with a total system volume of 20 μl containing 2.0 μl of 10 × Buffer, 0.5 ng of random ssDNA pool, 2.5 mmol/L Mg2＋, 0.25 mmol/L dNTP Mixture, 0.6 μmol/L upstream and downstream primers and 1.5 U of Taq DNA polymerase; the optimal annealing temperature was 68 ℃ and the optimal number of cycles was 12. Under the above conditions, clear and stable bands with high specificity for random ssDNA pool were amplified. [Conclusion] This study laid the foundation for selection of parameters with higher specificity in SELEX technology.

Effects of servo system on limited cutting width in CNC heavy cutting

A mathematical model of the computer numerical control (CNC) heavy cuttingservo system including chatter in cutting courses was constructed for the chatter in CNC heavycutting. The theoretical analysis, computer simulation and orthogonal tests on this model show thatincreasing the gain of position K_(pp) can improve the rapid tracking performance of machine tools,and decreasing the delay time of speed loop τ_s can quickly eliminate the static error in thesystem, but the limited cutting width b_(lim) will descend correspondingly; excessively large orexcessively small gain of speed loop K_(ps) can result in decreasing b_(lim); optimizing K_(pp),τ_s and K_(ps) can improve the dynamic and static performance of the system and increase b_(lim).It is easy and feasible to optimize the servo parameters by the orthogonal test. This method caneffectively improve the system's stability and limited cutting width and it is suitable for the CNCheavy cutting of heavy-duty machine tools.

Smashing Tissue Extraction of Flavonoids in Lophatherum gracileSmashing Tissue Extraction of Flavonoids in Lophatherum gracile

Objective] The study aimed to optimize the procedures for flavonoids ex-traction from of Lophatherum gracile. [Method] The powder of L. gracile leaf （3.0 g） was weighed and extracted fol owing an orthogonal design including the solid-liquid ratio, extraction time, extraction times and soaking time at three levels. [Result] The optimal parameters were solid-liquid ratio at 1：40, extraction time of 40 s, extraction times of two times and soaking time of 40 min. [Conclusion] Smashing tissue ex-traction of flavonoids is rapid and efficient, which provides a new method for the development and utilization of L. gracile.

Studies on the Super-high-yield Cultivation Techniques for Oats in Tibet

[Objective] The aim was to explore the optimal levels of different factors influencing oat yield in Lhasa, Tibet. [Method] Orthogonal test was conducted to analyze oat cultivation technology in Tibet. [Result] Qingyin No.2 and Baiyan No. 8 were proved the optimal species to be grown in Lhasa with optimal sowing quantity at 150-180 kg/hm2. Sowing term is an extremely significant factor affecting growing season, and species and N fertilizer are significant factors. Al factors have none significant effects on hay yield. [Conclusion] The research provides theoretical refer-ences and technological supports for large-scale planting.

Extraction of Perilla Seed Oil Using Supercritical Carbon Dioxide and GC-MS Analysis

[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oil was extracted using supercritical CO2 （SC-CO2）. The effects of extraction time, temperature and pressure were investigated by single-factor experiments and orthogonal array testing （ORT）. The chemical compositions of extracted perilla seed oil were investigated by GC-MS. [Result] The optimal conditions for the extraction of perilla seed oil using SC-CO2 were extraction time of 4 h, extraction temperature at 40 ℃, and extraction pressure at 23 MPa. Under these conditions, the extraction yield of perilla seed oil was maximized to 12.43%. GC-MS analysis revealed that perilla seed oil was a complex mixture containing 76.183% α-linolenic acid. [Conclusion] Supercritical CO2 extraction was proven to be an effective technology to extract oil from perilla seed, and GCMS was also a satisfactory method for analyzing the compositions of perilla seed oil.

Optimization of RAPD-PCR Reaction System for Glycyrrhiza uralensis Based on Orthogonal Design

[Objective] The aim was to obtain the optimum RAPD-PCR reaction system for Glycyrrhiza uralensis.[Method] Orthogonal design was adopted to screen the suitable concentration of four major factors（dNTPs,primers,Taq polymerase and DNA template） in PCR reaction system.[Result] The optimal reaction system obtained by orthogonal design was 25 μl in total volume,containing 2.5 μl of 10×PCR buffer solution（include MgCl2）,2.5 μl of 10 mmol/L dNTPs,2 μl（100 ng） of DNA template,2 μl of 10 μmol/L primers,0.4 μl（5 U） of Taq polymerase;the optimum annealing temperature was 34 ℃.[Conclusion] Orthogonal design was an effective method for the optimization of RAPD-PCR reaction system for G.uralensis.